Printing with mordant dyestuffs



Patented Sept. 27, 1938 PRINTING WITH MORDANT DYESTUFFS Emil Gubler,Basel, Switzerland, assignor to the firm Durand & Huguensin S. A. Basel,Switzerland No Drawing. Applicatio rial No. 123,726. In 1936 7 Claims.

In the U. S. patent application Ser. No. 716,001 are described processesfor printing with mordant dyestuffs (chrome dyestuffs) on fabrics ofanimal fibres, namely natural silk, and on fabrics of regeneratedcellulose such as viscose artificial silk, cuprammonium artificial silkand so on, in which the printing pastes used contain the mordantdyestuff, gum arabic thickening and a chromium mordant, having Cr in thecation in the presence of a lactate group. The principal advantage ofthe processes is to be found in the fact that the soft feel and thelustre of the fibre, which in the absence of the lactate group, owing tocoagulation of thearabic gum thickening in presence of the chromiummordant, would suffer, are retained. According to a particularlyadvantageous form of the processes chromium lactate is used. Theprocesses may also be combined with advantage with the process of U. S.Patent No. 1,848,589, according to which urea is also used in theprinting paste.

According to the hitherto usual procedure, after the prints thusprepared have been steamed they must be washed first with cold Water andthen with lukewarm water at about 40-50 C. in order that the fibres mayhave the desired soft feel. This procedure involves certaindisadvantages. For example, if basic dyestuifs are printed on thematerial together with the chrome dyestuffs, the prints of the basicdyestuffs are damaged by the treatment with lukewarm water and bleed.Moreover, the apparatus necessary for the treatment is not available inall silk printing works.

The present invention relates to an improvement whereby the treatmentwith lukewarm water is rendered unnecessary, and a completely soft feelof the fibres is attained by simply washing the printed material withcold water after steaming. For this purpose in accordance with theinvention there is added to the printing paste sodium tartrate or, ingeneral, an alkali salt of an aliphatic oXy acid such as tartaric acid,lactic acid, glycollic acid and so on.

If, as has hitherto been preferable, chromium' lactate is used in theknown process the present invention may be carried into effect by addingan alkali lactate, alkali tartrate or alkali glyco1- late to theprinting paste in addition to chromium lactate.

11 February 2, 1937, Se- Germany February 11,

The following examples illustrate the invention:

The following printing pastes are prepared:

Example l 2 3 Ohromocitronine R (Schultz, Farbstofltabel- Grams GramsGrams tabellen 7th Edn, N0. 999) -l 30 Dyestuil according to Example 1of German Specification No. 156234.. l. 30 Water 232 192 152 Formic acid(807) 30 .l Phenol l l 30 Furfuryl alcohol 10 Sodium tartrate cryst 3030 30 Gum arabic thickening (1 1) 610 610 610 Chromium lactate (14.7% OM38 38 38 Urea 60 60 100 25% solution of hydrosulphite NF The paste isprinted on natural silk or viscose artificial silk, and the material issteamed for 45 minutes, then washed with cold water and dried. There areobtained respectively yellow, blue and orange prints whilst the fibrehas an unobjectionable soft feel.

In the case of Example 2 the duration of the steaming can be appreciablyshortened by increasing the quantity of urea to 100 grams.

Sodium lactate or sodium glycollate can be used instead of sodiumtartratein the foregoing examples with similar effect.

The invention may also be applied in printing fabrics of otherartificial silks, such as fabrics of cuprammonium artificial silk.

What I claim is:--

1. In a process of steam printing with chromium mordant dyestuffs onlustrous fibres, including natural silk and regenerated cellulose fibre,such as viscose or cuprammonium artificial silk, an improvementconsisting in printing the material with a paste containing the mordantdyestuff, a gum arabic thickening, a chromium mordant having Cr in thecation in the presence of a lactate group, and an alkali salt of analiphatic hydroxy acid, thereby obviating the formation of a harsh feel,uneven dyeing and loss of lustre on the imprinted parts.

2. In a processor steam printing with chromium mordant dyestuffs onlustrous fibres, in-

cluding natural silk and regenerated cellulose V fibre such as viscoseor cuprammonium artificial silk, an improvement consisting in printingthe material with a paste containing the mordant dyestufi, a gum arabicthickening, chromium lactate, and an alkali salt of an aliphatic hydroxyacid, thereby obviating the formation of a harsh feel, uneven dyeing andloss of lustre on the imprinted parts.

3. As a new composition of matter, a printing paste containing a mordantdyestufi, a gum arabic thickening, a chromium mordant having Cr in thecation in the presence of a lactate groupand an alkali salt of analiphatic hydroxy acid.

4. A printing paste containing a mordant dyestufi, a gum arabicthickening, chromiumlactate and an alkali salt of an aliphatic hydroxyacid.

5. A printing paste containing a mordant dyestuif, a gum arabicthickening, chromium lactate and sodium tartrate.

6. A printing'paste containing a mordant dyestuff, a gum arabicthickening, chromium lactate and sodium glycollate.

7 A printing paste containing a mordant dyestuff, a gum arabicthickening, chromium lactate and sodium lactate.

EMIL GUBLER.

